I was wondering just what you meant by "breaks".

When I read your post, I thought you might mean something like ride 50 miles in the morning, rest a few hours and ride 50 miles in the afternoon. People generally don't do this.

Most people think of "breaks" in a century as stopping and getting snacks, taking a pit stop, getting water and letting their contact points have a break. For people who have a hard time doing a century, you can take a stop every 11/2 to 2 hours. I would recommend fewer stops early on and more in the second half. You can do that routine of "I get to stop at 85 miles" to get from 75 to 85 and then "only 15 miles to finish". It helps to mentally break up a ride. You don't want to stop very long though. That just makes it harder to warm up again.